RU2418898C1 - Composition for fire-proof treatment of polyamide fibres - Google Patents

Abstract

FIELD: chemistry. ^ SUBSTANCE: composition contains the following in pts. wt: methylphosphite borate 15, water 85, triethanolamine 0.25 and copper sulphate 0.38-1.50. ^ EFFECT: high fire-resistance, strength, resistance to thermal-oxidative decomposition and endowing polyamide fibre with high strength of binding with isoprene rubber. ^ 2 tbl, 4 ex

Description

The invention relates to the textile industry, to compositions for flame retardant processing of synthetic fibers, and can be used in aircraft, automotive, rubber industry and for other special purposes.

A known composition for fire-retardant finishing of textile materials from cellulose fibers, including the product of the interaction of nitrilotrimethylphosphonic acid with a nitrogen-containing substance and water, moreover, it contains urea as a nitrogen-containing substance (US Pat. 2184184 Russia, D06M 13/432; publ. 06.27.01).

However, the use of this composition requires drying the impregnated cord at high temperature and is intended only for materials from cotton, linen and viscose fibers.

A known composition for flame retardant processing of textile materials, including a derivative of chloroendic acid and an organic solvent, and in order to increase the fire resistance of materials made of polyamide or cellulose fibers, it additionally contains antimony trioxide (copyright certificate 953045 USSR, D06M 13/20; publ. 23.08.82).

However, this composition has a complex formulation, and a toxic substance is used as a solvent.

Also known composition for flame retardant chemical fibers based on a 5-7% aqueous solution of phosphorus-containing monomer (Fakril-M) using a redox system Fe ²⁺ -H ₂ O ₂ (application for invention 93012912 Russia; publ. 20.09 .96).

However, this composition must be grafted onto the fibers for a long time and at high temperature.

Closest to the invention in technical essence is a composition for flame retardant treatment of polyamide fibers, including a phosphorus-containing compound, water, and polyethylene polyamine is additionally used (patent 2344215 Russia D06M 13/50; publ. 20.01.2009).

However, this composition does not provide high fiber strength, resistance to thermal oxidative degradation, in addition, its preparation is accompanied by strong heating.

Objective: development of a composition for flame retardant treatment of polyamide fibers, providing increased fire resistance and physical and mechanical properties of the fibers.

The technical result is to increase fire resistance, strength, resistance to thermal oxidative degradation and giving the polyamide fiber increased bond strength with rubber based on isoprene rubber.

The technical result is achieved in that the composition for flame retardant treatment of polyamide fibers, including methyl phosphite borate and water, and additionally triethanolamine and copper sulfate in the following ratio of components, parts by weight: methyl phosphite borate - 15.00, water - 85.00, triethanolamine - 0.25, copper sulfate - 0.38-1.50.

We found that the reason for increasing the fire resistance of polyamide fibers is the formation of a thin fire-retardant film on the surface of the fibers, which inhibits the combustion process due to the formation of a foamed layer with better thermal conductivity, which limits the flow of oxygen to the combustion source.

The increase in fiber strength is due to the localization of microdefects on its surface with an impregnating composition, since microdefects are the root cause of fiber destruction when external stresses are applied to it.

The adhesion of the polyamide fiber to rubber increases, apparently, due to the appearance of new polar functional groups on the surface of the fiber, which enter into physical interaction with isoprene rubber.

Methyl phosphite borate has been used previously for flame retardant modification of cellulosic materials (RF patent 2254341 C1 C08B 15/05, publ. 06/20/05).

Triethanolamine (TU 6-02-916-79) is used as an absorbent of "acid" gases, as a raw material for the production of surfactants, in pharmaceuticals and cosmetics.

Copper sulfate (TU 2141-024-05774969-2003) is used as a mordant for dyeing textile materials, for preserving wood, for dressing seeds, as a pesticide, antiseptic and astringent medicine, pigment in paints, for leather dressing.

The use of this composition can significantly simplify the modification of polyamide fibers. So, to achieve a positive effect, the use of highly concentrated flame retardant compounds and the cooling of the prepared composition are not required. The use of a 15% aqueous solution of methylphosphite borate is most optimal. A decrease in the concentration of methylphosphite borate does not allow the self-extinguishing effect to be achieved, and an increase in the concentration reduces the strength of the fibers.

With a decrease or increase in the content of triethanolamine in the flame retardant composition, the flame retardant and strength properties of the polyamide fibers deteriorate.

With an increase or decrease in the content of copper sulfate in the impregnating composition, the fire resistance of the fiber decreases and the strength of the polyamide fiber decreases.

It should be noted that the use of this composition for flame retardant processing of polyamide fibers does not require high temperatures and complex hardware design.

An example of the preparation of flame retardant modifying composition.

Triethanolamine is poured into a stirred reactor containing a 15% aqueous solution of methylphosphite borate with stirring. Stirring is carried out for 1-2 minutes at room temperature, then copper sulfate is added and stirred for 5 minutes.

Get impregnating compositions 1-4, the formulation of which is shown in table 1.

Compounds 1-4 are impregnated for 1 minute with a polyamide cord grade 25 KNTS 1877 tex x1 x2 and dried at room temperature (20 ° C) to constant weight. Then thermostat for 30 minutes at 100 ° C.

The invention is illustrated by the following examples.

Example 1. Samples of polyamide fibers (20 cm long) are placed for 1 minute in a 15% aqueous solution of methylphosphite borate, previously neutralized with triethanolamine to ph 7 and containing 0.38 wt.h. copper sulfate, followed by drying at room temperature, then thermostating is carried out for 30 minutes at 100 ° C.

Examples 2-4 are carried out according to example 1, changing the content of copper sulfate.

The obtained samples are tested for resistance to burning (GOST 21793-76), tensile strength (GOST 20403-75), resistance to thermal oxidative degradation (studies were carried out at a temperature of 500 ° C for 30 minutes). The bond strength of the impregnated cord with rubber based on isoprene rubber (F.F.Koshelev et al. General technology of rubber. - M .: Chemistry, 1978. - p.57) was determined by the N-method (GOST 23785.7-89) on a tensile testing machine -60. The results are shown in table 2.

The table shows that with an increase in the content of copper sulfate, the physical and mechanical properties of the modified fibers improve. So, when processing polyamide fiber with a flame retardant according to recipe 4, the breaking load increases from 26.6 kgf to 34.7 kgf. In addition, modified fibers exhibit greater resistance to thermal oxidative degradation. The presence of a coke residue of 7.7% at 500 ° C in the polyamide fiber indicates the effective action of the flame retardant composition, as a coke formation catalyst during thermal oxidative degradation of the studied fibers. The use of this composition helps to increase the bond strength of the polyamide fiber with rubber, based on isoprene rubber, from 4.2 kgf to 4.7 kgf when using the composition of recipe 4.

Table 1 Composition Components The content of components, parts by weight one 2 3 four Methyl Phosphite Borate 15.00 15.00 15.00 15.00 Water 85.00 85.00 85.00 85.00 Triethanolamine 0.25 0.25 0.25 0.25 Copper sulphate 0.38 0.75 1.13 1,50

table 2 The properties Ref. fiber Performance for Compositions one 2 3 four Breaking load, kgf 26.6 28.6 28.5 32,5 34.7 Elongation mm 29.3 35.3 34.7 36.0 35.7 Fire resistance burns fades out fades out fades out fades out Coke residue (500 ° C 30 min.) 0 6.2 7.7 7.6 6.2 Adhesion to rubber, kgf 4.2 4.3 4,5 4.4 4.7

The technical and economic effect obtained from the use of this composition is that its use can significantly increase fire resistance, strength, resistance to thermo-oxidative degradation and adhesion to rubber based on isoprene rubber of polyamide fibers, reduce the consumption of reagents, does not require complex hardware design, long processing time, which avoids multi-stage processing.

Claims (1)

Composition for flame retardant treatment of polyamide fibers, including methyl phosphite borate and water, characterized in that it additionally contains triethanolamine and copper sulfate in the following ratio of components, parts by weight:
Methyl Phosphite Borate 15.00 Water 85.00 Triethanolamine 0.25 Copper sulphate 0.38-1.50